Fluorometric variable-temperature kinetics investigations of the transesterification reaction of procaine with aliphatic alcohols.

Variable-Temperature Kinetics has been used to obtain the rate constants of the reaction at various temperatures during one kinetic run. Pseudo-first-order rate constants for the transesterification of procaine with aliphatic alcohols ethanol, n-propanol and tert-butanol were obtained by the fluorescence spectroscopy using the variable-temperature kinetics (VTK) method. The activation parameters of the reactions were calculated (24-28 kcal x mol(-1)). The half-life of the procaine decreases in the ethanol solution compared with the other alcoholic solutions in the presence of sodium ethoxide. The investigation time of the reactions is reduced to one-tenth of the one used for usual kinetic methods.